Objective: Cisapride is a prokinetic drug with different reports on its cardiac side effects. As there might be a genetic susceptibility for the effects of this drug, we studied its effects on QTc interval of children in our region. Material & Methods: This semi-experimental study was performed on children aged over one month, who attended Amirkola Children's Hospital from October 2004 to March 2005 and needed to be treated with Cisapride. Patients with risk factors such as cardiac disease, electrolyte disturbance and drug usage interfering with Cisapride metabolism were excluded from the study. Cisapride was prescribed orally 0.6mg/kg/day in 3 doses. ECG was taken in lead II before drug administration and after one week. QTc intervals before and after treatment were compared. P-value >0.05 was considered significant. Findings: Among 135 admitted children needing Cisapride, 118 cases fulfilled inclusion criteria and were enrolled in the study. Their mean age was 14.1 (1.5) months. The mean QTc intervals before and after treatment were 377 (20) msec and 380 (22) msec, respectively (P=0.1). No child had a QTc interval more than 450 msec. Conclusion: Cisapride (0.6mg/kg/day) did not cause a significant prolonged QTc interval in children with no risk factor.

Background There is evidence indicating impaired cardiomyocytic contractility, delayed electrical conduction and increased electrophysiological heterogeneities due to iron toxicity in beta-thalassemia major patients. In the present study, we compared the electrocardiographic and echocardiographic features of betathalassemia major patients with a healthy control group. Materials and Methods The average annual serum ferritin levels of fifty beta-thalassemia major patients were assessed. For each patient, corrected QT (QTc) intervals and QTc dispersions (QTcd) were calculated and V1S and V5R were measured. All subjects underwent two-dimensional M-mode echocardiography and Doppler study and were compared with 50 healthy subjects as a control group. Results QTc interval and dispersion were significantly higher in beta-thalassemia major patients (P= 0. 001). The mean V5R (20. 04 ± 4. 34 vs. 17. 14 ± 2. 55 mm) and V1S (10. 24 ± 2. 62 vs. 7. 83 ± 0. 38 mm) showed considerably higher mean values in patients in comparison with control group. Peak mitral inflow velocity at early diastole and early to late ratio in the case-group was markedly higher (P<0. 001), whereas, early deceleration time (P=0. 01) and Isovolumic relaxation time (IVRT) (P=0. 001), were meaningfully lower than the control group. There was positive correlation between age and QTc (r= 0. 831, P=0. 001) and QTc dispersion (r= 0. 710, P=0. 001) and negative correlation between serum level of ferritin and V5R (r=-0. 271, P= 0. 05). Conclusion Measurement of the QTc interval and dispersion can be used for early detection of cardiac involvement, especially in asymptomatic beta-thalassemia patients with ferritin levels higher than 2, 500 ng/dl.

Background- Cardiovascular complications are the most common cause of mortality and morbidity in non-insulin dependent diabetes mellitus (NIDDM). Autonomic neuropathy is one of the complications of NIDDM, which may also involve the cardiovascular system. Autonomic system abnormality may increase the QTc interval. On the other hand, patients with prolonged QTc interval are prone to ventricular arrhythmia, especially unique torsade-de-points and also sudden cardiac death. This study intends to detect the prevalence of QTc prolongation in diabetic and non-diabetic patients as well as its correlation with diabetic autonomic neuropathy. Methods and Results- This study includes 200 diabetic (case) and 200 non-diabetic patients (control group) with comparable age and gender. Evaluation of autonomic nervous system was carried out in all cases with prolonged QTc interval as well as in the control group.  The results of study in the case and the control group were compared. The prevalence of prolonged QTc interval was significantly higher in the case group in comparison with the control group, 8% vs. 2%, respectively (p value = 0.012, OR = 4.3). Sympathetic nervous system evaluation in cases with QTc interval prolongation and negative exercise test demonstrated abnormal results in more than 50% of the case group (OR = 3). Parasympathetic nervous system evaluation test in the case group showed abnormal results in comparison to the control group (OR = 9). Abnormality of the parasympathetic nervous system was three times more common than abnormality in the sympathetic nervous system. Conclusions- With regard to the prolonged QTc interval in the case group in comparison with the control group and abnormal autonomic nervous system function in more than half of the case group, the probability of ventricular arrhythmia, torsade de points, is increased. The mentioned group is at increased risk of sudden cardiac death. Rendering approaches for decreasing the risk of sudden cardiac death in diabetic patients is seriously recommended

Background and aim: Brain trauma is one of the most important causes of morbidity and mortality, especially in the urban and industrial societies. Risk factors that increase the mortality of the patients are aging, other organs trauma and cardiac arrhythmia. Some of the ECG abnormalities following traumatic brain Injury are tachy-arrhythmia, brady-arrhythmia, increased QTc interval and changes in ST segment. Traumatic brain patients also show subarachnoid hemorrhage (SAH) and increased QTc intervals. Our aim in this study is to evaluate QTc interval changes in patients with moderate to severe brain injury.Methods: This retrospective study was performed on 200 patients with moderate to severe head injury, who were admitted in AI-Zahra and Kashani hospitals, in Isfahan city, Iran, between years 2004-2006. QTc interval (based on Bazett formula) and level of consciousness (based on Glasgow coma scale) were obtained from the patients' files. Data were analyzed using student t-test and Chi-square test.Results: The most common injury in the patients was intracranial hemorrhage (ICH). Our study did not show any correlation between age and level of consciousness with QTc interval (P>0.05). The most common cause of mortality in our patients was subarachnoid hemorrhage (SAH). There was no significant correlation between causes of injury and patient's mortality (P>0.05). Evaluating QTc intervals from the files of the patients who were died showed that they had longer QTc interval compared to the alive patients' (P<0.01). QTc interval was longer in women compared to men (P<0.05). A direct correlation was seen between decreased level of consciousness and QTc interval elongation (P<0.001).Conclusions: Our findings show that QTc interval can be used as a good index for mortality in the patients with moderate to severe brain injury. QTc interval prolongation has correlation with severity of consciousness loss and mortality.

Introduction. Cardiovascular disease is a major public health problem in developing and developed countries. Smoking is themost modifiable risk factor for atherosclerotic heart disease. Acute cardiac events such as ventricular fibrillation and sudden cardiac death are increased by cigarette smoking and QT interval prologation associated with a lowered threshold of this events.Methods. The study included a sample of 160 healthy subjects of 20-59 year old men in four groups. First group was nonsmoker and others were smoker (<10, 10-20,>20 pack - year). all subjectswere age - matched.All subjects underwent a routine 12-lead electrocardiogram at rest. Then QT interval and QT dispersion were measured and corrected by bazett, fridercia and linear regression formulas. Comparison of data between these groups was performed with the ANOVA test.Results. Corrected QTc max was significantly increased in smokers compared with nonsmokers (P<0.00l) and in >20 pack - year smokers was significantly increased compared with <10 pack - year smokers (P<0.00l). QTc dispersion was significantly increased in smokers compared with nonsmokers (P<0.00l) but there is no significant difference between smokers. Correlation between these formulas in correction of QT interval was greater than 95% in pierson test.Discussion. Smoking prolonges QTc interval and QTc dispersion. This effect together with increase in sympathetic tone and decrease in vagal tone and blunted barroreceptor gain can result increase in coronary and arrhythmogenic events in smokers.

Background and Objective: Methadone is a synthetic opioid which is used in opium addiction therapy and relief of acute and chronic pain. Side effects of Methadone were reported on heart and induction of Torsade De Pointes disease and increase QTc interval in electrocardiogram. This study was conducted to determine the effect of Methadone therapy on QTc interval in electrocardiogram and its relationship with dosage and duration of Methadone therapy.Method: This cohort study was conducted on 60 opium addicted patients (57 males, 3 females) whom referred to “Methadone Therapy Clinic” in 5 Azar teaching hospital in Gorgan, northern Iran during 2009-10. Patients were divided to three groups based on the dosage of methadone: 0-35 mg (27 cases), 35-55 mg (27 cases) and 55-120 mg (26 cases) per day. QTc interval in electrocardiogram was measured at the beginning of study, one month and 5 months afterward.Results: The mean±SD of QTc interval in patients at the beginning, one month and 5 months afterward of study was 0.42±0.027, 0.43±0.029 and 0.43±0.041 seconds, respectively. There was a significant increase in QTc interval after one month of methadone therapy, compared to the beginning of study. There was no significant difference in QTc interval between 1 month and 5 months following methadone therapy. There was no significant difference between QTc interval and different dosage of methadone.Conclusion: Methadone therapy increase QTc interval but there is not any relationship between dosage and duration of methadone therapy and QTc interval.